/**
 * MOAB, a Mesh-Oriented datABase, is a software component for creating,
 * storing and accessing finite element mesh data.
 *
 * Copyright 2004 Sandia Corporation.  Under the terms of Contract
 * DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government
 * retains certain rights in this software.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 */

#ifdef WIN32
#ifdef _DEBUG
// turn off warnings that say they debugging identifier has been truncated
// this warning comes up when using some STL containers
#pragma warning( disable : 4786 )
#endif
#endif

#include "WriteSmf.hpp"

#include <fstream>
#include <iostream>
#include <cstdio>
#include <cassert>
#include <vector>
#include <set>
#include <iterator>
#include <algorithm>

#include "moab/Interface.hpp"
#include "moab/Range.hpp"
#include "moab/CN.hpp"
#include "MBTagConventions.hpp"
#include "moab/WriteUtilIface.hpp"
#include "Internals.hpp"
#include "moab/FileOptions.hpp"

namespace moab
{

const int DEFAULT_PRECISION = 10;
// const bool DEFAULT_STRICT = true;

WriterIface* WriteSmf::factory( Interface* iface )
{
    return new WriteSmf( iface );
}

WriteSmf::WriteSmf( Interface* impl ) : mbImpl( impl ), writeTool( 0 )
{
    assert( impl != NULL );
    impl->query_interface( writeTool );
}

WriteSmf::~WriteSmf()
{
    mbImpl->release_interface( writeTool );
}

ErrorCode WriteSmf::write_file( const char* file_name,
                                const bool overwrite,
                                const FileOptions& opts,
                                const EntityHandle* output_list,
                                const int num_sets,
                                const std::vector< std::string >& /* qa_list */,
                                const Tag* /* tag_list */,
                                int /* num_tags */,
                                int /* export_dimension */ )
{
    ErrorCode rval;

    // Get precision for node coordinates
    int precision;
    if( MB_SUCCESS != opts.get_int_option( "PRECISION", precision ) ) precision = DEFAULT_PRECISION;

    // Honor overwrite flag
    if( !overwrite )
    {
        rval = writeTool->check_doesnt_exist( file_name );
        if( MB_SUCCESS != rval ) return rval;
    }

    // Create file
    std::ofstream file( file_name );
    if( !file )
    {
        MB_SET_ERR( MB_FILE_WRITE_ERROR, "Could not open file: " << file_name );
    }
    file.precision( precision );

    // Get entities to write
    Range triangles;
    if( !output_list || !num_sets )
    {
        rval = mbImpl->get_entities_by_type( 0, MBTRI, triangles, false );
        if( MB_SUCCESS != rval ) return rval;

        // Somehow get all the nodes from this range, order them, uniquify, then use binary search
    }
    else
    {
        // Get all triangles from output sets
        for( int i = 0; i < num_sets; i++ )
            rval = mbImpl->get_entities_by_type( output_list[i], MBTRI, triangles, false );
    }
    // Use an array with all the connectivities in the triangles; it will be converted later to ints
    int numTriangles    = triangles.size();
    int array_alloc     = 3 * numTriangles;               // Allocated size of 'array'
    EntityHandle* array = new EntityHandle[array_alloc];  // ptr to working array of result handles
    // Fill up array with node handles; reorder and uniquify
    if( !array ) return MB_MEMORY_ALLOCATION_FAILED;
    int fillA = 0;
    for( Range::const_iterator e = triangles.begin(); e != triangles.end(); ++e )
    {
        const EntityHandle* conn;
        int conn_len;
        rval = mbImpl->get_connectivity( *e, conn, conn_len );
        if( MB_SUCCESS != rval )
        {
            delete[] array;
            return rval;
        }
        if( 3 != conn_len )
        {
            delete[] array;
            return MB_INVALID_SIZE;
        }

        for( int i = 0; i < conn_len; ++i )
            array[fillA++] = conn[i];
    }
    if( fillA != array_alloc )
    {
        delete[] array;
        return MB_INVALID_SIZE;
    }

    std::sort( array, array + array_alloc );
    int numNodes = std::unique( array, array + array_alloc ) - array;

    file << "#$SMF 1.0\n";
    file << "#$vertices " << numNodes << std::endl;
    file << "#$faces " << numTriangles << std::endl;
    file << "# \n";
    file << "# output from MOAB \n";
    file << "# \n";

    // Output first the nodes
    // num nodes??
    // Write the nodes
    double coord[3];
    for( int i = 0; i < numNodes; i++ )
    {
        EntityHandle node_handle = array[i];

        rval = mbImpl->get_coords( &node_handle, 1, coord );
        if( rval != MB_SUCCESS )
        {
            delete[] array;
            return rval;
        }

        file << "v " << coord[0] << " " << coord[1] << " " << coord[2] << std::endl;
    }
    // Write faces now
    // Leave a blank line for cosmetics
    file << " \n";
    for( Range::const_iterator e = triangles.begin(); e != triangles.end(); ++e )
    {
        const EntityHandle* conn;
        int conn_len;
        rval = mbImpl->get_connectivity( *e, conn, conn_len );
        if( MB_SUCCESS != rval )
        {
            delete[] array;
            return rval;
        }
        if( 3 != conn_len )
        {
            delete[] array;
            return MB_INVALID_SIZE;
        }
        file << "f ";
        for( int i = 0; i < conn_len; ++i )
        {
            int indexInArray = std::lower_bound( array, array + numNodes, conn[i] ) - array;
            file << indexInArray + 1 << " ";
        }
        file << std::endl;
    }

    file.close();
    delete[] array;
    return MB_SUCCESS;
}

}  // namespace moab
